1999 article
Effect of nitrogen incorporation on electron emission from chemical vapor deposited diamond
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, Vol. 17, pp. 734–739.
Two different types of the nitrogen-doped chemical vapor deposited (CVD) diamond films were synthesized with N2 (nitrogen) and C3H6N6 (melamine) as doping sources. The samples were analyzed by scanning electron microscopy, Raman scattering, photoluminescence spectroscopy, and field-emission measurements. More effective substitutional nitrogen doping was achieved with C3H6N6 than with N2. The diamond film doped with N2 contained a significant amount of nondiamond carbon phases. The sample produced with N2 exhibited a lower field emission turn-on field than the sample produced with C3H6N6. It is believed that the presence of the graphitic phases (or amorphous sp2 carbon) at the grain boundaries of the diamond and/or the nanocrystallinity (or microcrystallinity) of the diamond play a significant role in lowering the turn-on field of the film produced using N2. It is speculated that substitutional nitrogen doping plays only a minor role in changing the field emission characteristics of CVD diamond films.